I. Field of the Invention
This disclosure relates generally to systems, apparatus and methods for geofences, and more particularly to communicating and using a geofence based on an RF fingerprint while maintaining privacy.
II. Background
A geofence may be defined by a circle with a center determined by a global navigation satellite system (GNSS) or global positioning system (GPS) coordinate (latitude and longitude) and having a radius (R). A traditional geofence defines an area where an application executes based on entering and/or exiting the geofence. A mobile device includes a low power consuming modem that determines when the mobile device crosses the geofence and a high power consuming application processor to execute the specific application. The low power consuming modem contains a global navigation satellite system (GNSS) or global positioning system (GPS) receiver. The high power consuming application processor contains the specific application. The mobile device uses the GNSS receiver to determine when a current location of the mobile device has crossed between inside and outside a geofence. When the mobile device determines it is leaving or entering a geofenced area, the mobile device wakes the high power consuming application processor to execute the specific application.
The above technique communicates a geofence on an open channel using GNSS results. However, there are a few key problems that cannot be solved by this approach. First of all, a geofence reveals an absolute location of the geofence in violation of privacy concerns. Also, a geofence may take a substantial amount of bandwidth to communicate. What is needed is a means to define and use a geofence when privacy of a geofence needs to be maintained and when use of limited bandwidth is desired.